Ninja of Gravity Falls
by mellra
Summary: When Dipper and Mabel went to visit their Grunkle Stan for the summer, they were introduced to the three workers of the Mystery Shack. They learn that one of the biggest mysteries is the strange blonde teen with whisker marks who works for Stan. Challenge Fic.


**Disclaimer:** I own neither Naruto nor Gravity Falls. I wish I did though.

 **AN:** Recently I was introduced to Gravity Falls by my friend Ygvan Lord of Worlds a month ago and I am now a huge fan! This idea then came to me to write a Naruto/Gravity Falls crossover challenge as there are not many stories of this category. The idea goes like this:

When Naruto and Sasuke clash at the Valley of the End at the end of the Retrieval mission, the mixing of the unstable chakra causes a rip to appear in space-time. Sasuke manages to kick Naruto through the rift and it seals up behind him. Naruto ends up in a limbo like dimension where time is frozen for him so he doesn't age or die. While there, Naruto goes temporarily mad, then sane, then trains his techniques, and eventually befriends Kurama.

Then one day, a crack appears in the dimension and Naruto, seeing his chance, forces his way through. However, he doesn't wind up in the Elemental Nations. Meanwhile, Stan Pines hears the dimensional gateway opening up briefly and, thinking Ford made his way back, rushes to go see but instead finds an unconscious blond kid.

Eventually, Naruto wakes up and Stan asks him where he's from and all that and when Naruto explained, Stan tells him he found the boy out in the woods somewhere and its unlikely he can go back to his own dimension/time since him winding up in Gravity Falls was completely random and without a way to recreate the way back he was stuck there. Stan then offers Naruto to stay in the Mystery Shack and work for him since he has nowhere to go.

Naruto agrees and 3 years later, Stan tells Naruto that his grandniece and nephew is coming to stay for the summer. Naruto will be 15-16 at this time and will possibly date Wendy later in the story. Also, while he won't know a ton of Jutsu, he will perfect the ones he knows and will have a decent friendship with Kurama. He'll also join Dipper and Mabel on their adventures while keeping his own past a secret at the beginning.

This _**CHALLENGE**_ is available for anyone to adopt, just please let me know if you are interested either by PM or Review. Since this is a _**CHALLENGE,**_ that means it won't be updated unless someone adopts it so if you or someone you know would be interested, please don't hesitate to ask. In the meantime, enjoy my madness! MWAHAHAHA!

 **Ninja of Gravity Falls**

How long? How long has he been floating in this eternal limbo? Hours? Days? Months? …Years? Time had no meaning here, so pondering such questions became meaningless after so long. There were times where he felt like he was losing his mind. There were times where he DID lose his mind. Then there were times he found his mind again to start the cycle anew. There was one thing he knew for sure though no matter how much time passed in this accursed void: his name is Naruto Uzumaki.

It all started with a mission, a rescue mission to save a friend that had lost his way in his own darkness. There were many challenges, ones that children, even ninja children, should never have to face but somehow he and his teammates pulled it off. It was at the Valley where he alone confronted his friend who left their home for power. They fought, calling on powers that even seasoned warriors had trouble comprehending. Neither seemed to have an advantage, both were testing the limits of their resolves. Then the final clash came, corrosive red chakra vs. tainted purple and black chakra. The two unstable energies mixed, forming a dome of pure energy that surrounded the two boys. There was a crack in the dome, and the fallen one pushed him into it and the crack sealed behind him, trapping him for all eternity in this hellish prison. Unable to age, unable to die, he simply existed.

After a week, or what felt like a week, of trying to escape through different means, Naruto had come to the conclusion that he was well and truly trapped here. He had even tried summoning one of the Toads to see if they could get him out of here or failing that let the Pervy Sage know what happened to him, but nothing happened when he attempted the Summoning Jutsu. There were times where he felt like ending it all, but holding onto the thin hope that he'd be free someday coupled with his natural stubbornness kept him going. As for what passed for time went by, Naruto grew desperate for someone to talk to. There was even a period where he made several Shadow Clones just to have a conversation, but it was hollow to say the least. Finally, when he couldn't take the complete silence and isolation anymore, he went into his mindscape to talk to the one being he knew was still around, even if he was reluctant to engage him in conversation: the demon sealed within him.

To say that the first few conversations were awkward would be like saying getting stabbed by a lightning based jutsu kind of hurt; a massive understatement. The Nine-Tailed Fox was anything but pleased about his situation, as not only had his container failed to beat that 'Uchiha brat', but he had gotten himself imprisoned which made the Tailed Beast doubly imprisoned. There was much yelling and cursing out, as well as threats of dismemberment, until the two had shouted each other hoarse. Then, surprisingly, the two started to actually talk. Granted, the earlier talks were full of biting comments and sarcastic remarks, but soon the two started to actually see past the hatred they had for each other and began talking for real, discussing things like their pasts, their likes, and even things like dreams for the future. It is amazing what near complete isolation can do to people, it can even cause them to talk to someone they'd never thought they could get along with in their lifetime, but here we are with the jinchuriki and his Tailed Beast becoming friends. It had even gotten to the point that Naruto learned the Fox had a name; Kurama.

Now that he had someone to talk to, Naruto began to get out of his funk a bit. Eventually, Naruto decided that he'd make the best of his eternal prison and began to train. He first started on the techniques he knew and worked on perfecting them. Soon, he could perform the Rasengan without relying on a clone to stabilize it and could even form Shadow Clones seallessly. He had even taken up an interest in sealing during this time, and he used the few storage scrolls and explosive tags he carried on him as a base for his studies. It turns out he was pretty good at seals and was able to make some of his own using pieces of paper he had on him. Finally, Naruto began training to use Kurama's chakra for real and was making steady progress with it. He could now go up to six tails worth of his chakra without getting overwhelmed, but even with his newfound skills and abilities he was no closer to escaping his prison. This brings us to now, with Naruto floating aimlessly through the void.

'I can't help but wonder…am I going to spend all of eternity? Am I ever going to see Konoha again?' he thought as talking out loud had grown pointless the longer he spent here.

" **You know thinking like that is pretty much pointless Naruto,"** the deep voice of Kurama rumbled in his mind. **"And yet you always seem to think it at least once."**

'I guess I can't help but hope that I will be able to get out of here one day,' the blonde thought.

" **As much as I hate to admit it, I doubt there is a way out. The rift that that accursed Uchiha kicked us through was formed by a clash of your two unstable chakras. The only way to get out is if something similar was formed to provide a door out, and even then it is doubtful it would lead us back to the right place or even time. Which is bad for you, worse for me because now I'm twice trapped and since you can't die in this purgatory, that means we're both trapped for all eternity."**

Naruto sighed as he continued to float through the void. However, something different happened as he floated within areas he'd never been before (though this was difficult to tell as everything looked exactly the same). It was faint, but he saw what looked like a crack forming in the white space. 'Is that-?!' Naruto thought frantically.

" **I-I literally don't believe it!"** Kurama said in shock before realizing what this meant and shouted, **"NARUTO! Use my chakra and attack that crack full power! This is our ticket out of here!"**

Without a second thought, a dark red cloak sprang up around him until he looked like a miniature Kurama with six tails and a fox skull and spine. Holding out a clawed hand, a deep purple orb of spiraling chakra forming in it. **"RASENGAN!"** the Kyuubified Naruto shouted as he slammed the attack into the crack. The ninja roared as he pushed against the crack harder and harder, forcing the distortion to spread until, with a sound not unlike breaking glass, he pushed his way through. There was then a sensation of falling as the chakra cloak receded and then there was blackness.

 **Scene Skip: Gravity Falls, Oregon**

In a dingy tourist trap called the Mystery Shack, a middle aged man (1) named Stan Pines jolted awake as he heard a rumbling coming from the secret basement of the building. He blinked as he pulled on his glasses and went to the entrance of the basement hidden behind the snack machine. Opening the door, Stan could only gasp as he saw lights sparking from downstairs…right where his brother's transdimensional gateway was stored.

"Ford…?" Stan muttered, wondering (and hoping) if it was possible that his long lost twin brother had found a way to open the portal from the other side. Grabbing a bat he kept behind the counter of the Mystery Shack to keep people from getting too grabby with the cash register, Stan cautiously made his way downstairs. The con artist, while hoping that it was his estranged brother, wasn't taking any chances that it could be something else opening the gateway. After all, he hasn't survived as long as he had by being _completely_ reckless.

Going down the path to the basement (while noticing the light was growing stronger the closer he got), Stan arrived in the lab just as there was a shattering sound followed by a thump and the light died down. Peering through the viewing window to the gateway room, the elder Pines saw a figure lying before the gateway and that the figure was roughly human shaped from what he could tell.

"FORD!" Stan shouted as he forgot all precautions and ran to the figure, dropping the bat in the process. However, when he got closer to the figure he noticed that it wasn't his six-fingered twin. Instead, what he found was a blonde kid that couldn't have been much older than thirteen completely out cold on the floor. "What the…? How'd a kid get down here?" Stan muttered as he bent down to inspect the mysterious visitor.

The boy, for Stan could tell it was a he, was somewhat small for his age and wore a bright orange jumpsuit that hurt Stan's eyes from staring at it too long. Pulling back an eyelid, the owner of the Mystery Shack noticed the boy's eyes were bright blue and his blonde hair was spikey and went in all directions. What was really odd about the kid though was that he had what looked like whisker marks on both cheeks (Stan figured they were either birthmarks or tattoos, knowing that kids today got into all kinds of crazy crap), and he wore a headband of sorts that had a metal plate on it that seemed to have some kind of stylized leaf on it.

Scratching his head in confusion, Stan wondered out loud, "Where'd you come from kid? And more importantly, what the heck am I gonna do with you?"

 **Time Skip**

Naruto groaned as consciousness slowly came back to him. 'Ugh…did anyone catch the number of that train that hit me?' he thought as he squinted his eyes shut tightly against the light leaking through his eyelids. Then the events of the previous night hit him and all traces of grogginess vanished in an instant. Bolting up from his position, Naruto's eyes snapped open to take in his surroundings. Looking around, he saw that he was in what looked like a house mixed in with a museum. Various odds and ends littered the area such as strange looking statues and taxidermy animals that looked to be glued together. The displaced shinobi saw that he had been lying on a lumpy couch and a ratty blanket had been thrown over him at one point, so it was clear someone had found him and taken him here, wherever _here_ was.

'Kurama, you awake?' Naruto mentally called out to his tenant.

" **Ugh…I am now. What do you want brat?"** Kurama yawned.

'I think…I think we're finally out of that prision we were in, but I have no idea where we are now. Do you think you could check and see if there is anyone in the area?' the blonde asked.

" **I'm actually surprised at the amount of forethought you're displaying, especially because I figured you'd be jumping around like a grasshopper on caffeine now that we're out of that void of eternal boredom. Just give me a second,"** Kurama complimented before stretching out his senses through his host to detect for anyone nearby. What he found shocked him. **"Naruto…I found someone, but…there is something seriously wrong here."**

'What is it Kurama?' Naruto thought, wondering what could have the self-proclaimed 'Strongest Tailed Beast' on edge.

" **From what I can tell, the person I'm sensing doesn't have a chakra network. And I don't mean like they have too small of one or that they're not an actual person, but that they literally have no chakra network. Plus, they're exhibiting all the signs of being a living being, but that shouldn't be possible. They should technically be dead without any chakra!"** Kurama thought in worry.

Before Naruto could figure out a proper response to that, he heard someone approaching the room he was in. Turning to the doorway, Naruto saw a man walk in. The man seemed to be a few years older than Pervy Sage and Granny Tsunade, but still seemed to be in shape somewhat. He was fairly tall and wore a black suit, white shirt, red bowtie, and some kind of red fez with a strange symbol on it. He also wore large glasses on a slightly large and orange colored nose, and had stubble decorating the lower half of his face.

The two stared at each other for a minute or two before the man spoke in a gravelly voice, "Glad to see you're up kid. Found you out in the woods last night a few miles from my house and brought you here 'cause the nearest hospital is a ways off. Plus, I couldn't find any ID or insurance on you, so take it from me that those quacks they call doctors there get a hold of you, they'd bleed you dry of every penny you own. Mind telling me what you were doing out there kid and where you came from?"

Naruto coughed as his voice hasn't been used in what felt like an eternity and answered, "I-I'm not really sure. Could you tell me where I'm at?"

The old man grunted and said, "Eh, sure kid. You're in Gravity Falls, Oregon. And this," he gestured to the area around them, "is the Mystery Shack, home of the weird and unexplainable. Also it's my house."

Naruto's mind was buzzing, 'Where do you think we are, Kurama? I've never heard of "Gravity Falls" or "Oregon for that matter. Where the heck are we?!'

" **Calm down kid before you hurt something. I've thought about it, and there's only one real explanation that makes any sense to us winding up in some unknown land and the people here not having chakra: we're in an alternate dimension."** Feeling Naruto's confusion, the fox explained, **"It's like this; that place we were in before was like a gateway between two worlds. On the one end is our world with everything we left behind, while on the other end is this world where everything seems different. You went in through one end when fighting that Uchiha, but came out the other end when you blasted open that crack. Now we're stuck here, and to be perfectly honest I have no idea if there's a way back. No way that would actually work in any case."**

Naruto felt a brief but sharp stab of depression at the fact that going back home seemed even further out of his reach then it did before. He shook himself out of it for the moment when he noticed that the man was looking at him expectantly. Figuring that he'd think more on this later, Naruto decided that he'd play the amnesia/confusion card for now.

"Ah, I'm not actually sure where I came from Gramps. I remember my name and some other stuff, but I can't really recall where I'm from or how I got here," Naruto said in what he hoped was a convincing tone.

The man took a breath through his nose before letting it out through his mouth and fixed his surprisingly sharp gaze on him. "Kid, did anyone ever tell you to never try and out con a con man? That whole 'amnesia' trick is literally the oldest trick in the book when it comes to dodging questions." Noticing Naruto was about to protest, he raised his hand to stop him from saying anything else. "It's alright blondie, I of all people know there are some things people don't want to talk about. I just have a few questions for you and I want you to answer them honestly, 'kay?"

Hesitantly, Naruto nodded and the man held up a finger. "First question, are you a cop? Because you gotta tell me if you're a cop." Seeing Naruto shake his head, Stan let out a mental sigh of relief. That was one bullet dodged. Holding up a second finger he asked, "Second question, are you in any way, shape, or form a threat to me or the people of this town?" Another shake of the head and a third finger raised. "Third, do you have a place to stay or at least know somewhere you can stay?" Another shake, another finger. "Fourth, what's your name, kid?"

Naruto grinned and pointed at himself, "The names Naruto Uzumaki, Believe it!" He was half tempted to add on the rest of his usual introduction, but held off as he doubted 'I'm gonna be the next Hokage,' would make any sense to the self-proclaimed con man. Plus, as much as he hated to admit it, his dream looked to be getting closer and closer to being impossible to reach.

The man cocked an eyebrow and grunted, "Stan Pines, and don't you ever do that again." He said referring to the blonde's verbal tick. "Also, don't call me Gramps, I ain't a grandpa. You can call me Mr. Pines or Stan if that's too much of a stretch for yah. Anyway, weird named kid whose name I'm probably going to forget, last question; do you want a job?"

This took Naruto by surprise and he asked, "You-You're offering me a job? Why? We literally just met and I'm not familiar with the area or how to run a…Mystery Shack?...or whatever."

Stan shrugged. "Couple reasons I'm offering to hire you actually. For starters, I could always use an extra hand around here to help run the place. Plus, this way I can keep an eye on you. You said you're not a threat and I believe you, but I'd rather have you in spitting distance just in case. After all, I found you and that makes you my responsibility or some such sentimental garbage. Finally, I'm actually kind of familiar with being down on your luck and having no place to go, so see this as me paying back a lifetime of bad karma. 'Sides, the work I'm going to train you to do for me isn't going to be easy, so see it as an even trade with me getting some help around the Shack and you getting a place to stay at with some money on the side. Sound good?"

Naruto thought it over for a moment. 'What do you think, Kurama?'

The Tailed Beast grunted, **"I'd say go for it. While this guy is shadier than a forest floor, I can't detect any ill intentions towards us. And when you think about it, this offers you the perfect opportunity to both have a place to stay at and find out more about this world we've landed in."**

Mentally nodding, Naruto answered, "Alright Stan, I accept." He then held out his hand and shook it with the older man's hand.

Stan grinned, "Okay Na-whatever. Let me show you your room for now and then we can start going over some of your duties later. Then tomorrow I'll show you your coworkers and stuff."

Naruto, getting off the couch, followed Pines up the rickety stairway and couldn't help think, 'Well, maybe this new world won't be so bad.'

Meanwhile, Stan was thinking, 'Here's hoping keeping you here isn't a mistake kid. I also hope I can find out where you came from and if you've seen my brother. Only time will tell I guess…'

 **Time Skip (3 Years Later)**

"Whiskers! Get your butt down here!" the rough voice of Stan Pines shouted from within the Mystery Shack.

'Whiskers' AKA a fifteen year old Naruto Uzumaki looked up from his place on the roof. Glancing at the half finished 'S' he was in the process of renailing, he shrugged, "Eh, good enough. Doubt it will fall off any time soon." With that, he tucked his hammer into the holder on his tool belt and easily jumped off the roof to the ground below when he was sure no one was looking, sticking the landing perfectly.

The years have been kind to the former shinobi during his time in Gravity Falls. He was no longer the shortest kids his age, he now stood at a height of nearly six foot and had a lean athletic build. While his facial features were the same, they lacked the baby fat they previously carried. He now wore a burnt orange tee shirt (which he had sown his signature red spiral onto), khaki shorts held up by a tool belt, orange sneakers, and the necklace he won from Tsunade hanging proudly on his neck. He still used his headband to keep his longer hair out of his eyes, but he had replaced the band with a black bandana. He had been living in this new world for three years now, and had become well-adjusted to his new life. Granted, he still missed the Hidden Leaf and kept an eye open for a way back, but the ache had dulled some over time and he was more accepting that this world was his home now.

Going to the front of the store, Naruto spot Soos working on one of the Mystery Shack's porch lights. Soos, like Naruto, was a handyman Stan had hired ten years ago and had helped Naruto learn his way around the tourist trap. He was a large young man with an even larger heart and a childish sense of wonder about him, and the two soon became close friends. Soos stood up and brushed off his Mystery Shack tee shirt before turning and giving the blonde a friendly wave. "Oh hey Nar! Mr. Pines is looking for you."

Waving back Naruto called, "Yeah I heard him Soos. I'm on my way to see what the old man wants."

With that, Naruto walked into the Shack. Inside, Naruto saw Stan Pines standing by the counter and was looking at his watch. Turning to see the whiskered teen walking in, Stan said, "Hey Whiskers, you done with your job yet?"

Thinking of the half nailed on sign above the building, Naruto shrugged, "Done enough."

Stan just grunted in an unconcerned manner, "Well if you got a minute, I want you to come with me to the bus station to pick up Dipper and Mabel. They're due to arrive any minute, and I don't wanna pick up any cab fares because they got impatient."

Nodding, Naruto turned to his second coworker, "Hey Wendy, can I borrow the keys to the golf cart?"

The redheaded fifteen year old girl smirked from her spot behind the counter and put down her magazine that she was reading before tossing the keys to the former ninja who caught them with practiced ease. "Go nuts Whiskers," she said casually while winking at him.

Naruto felt his cheeks heat up a bit at that. Naruto had met the outdoorsy girl soon after coming to this world when Stan (using some pretty shady paper work) got him enrolled in the local school. The two hit it off almost immediately thanks to their personalities going together so well. She was relaxed, down to earth, and had a rebellious streak while he was goofy, energetic, and was easy to get along with. The two were platonic for now, but the other members of their group of friends had started taking bets on who'd ask who out first. (It was four to one in Wendy's favor.)

"Thanks Wendy," Naruto chuckled and headed out the door with Stan in tow. The owner of the Mystery Shack himself had grown on the blonde over the years. While he might be crass, a con man, and quite possibly a felon in multiple states, the man was almost like a father figure to the teen. While they could never replace the people from Konoha in his heart, in their own way each member of the Mystery Shack had become like family during his stay in this world. Driving the golf cart (while silently wishing he could just use his actual speed to run), Naruto and Stan soon arrived at the bus station in town. While they waited for the bus to arrive, Naruto turned to Stan, "So, your great niece and nephew…they're staying the whole summer?"

Stan nodded as he eyed a magazine entitled 'Old but Datable'. "Yeah, they'll be here until before school starts up again. Pain in the butt if you ask me, but I guess I won't say no to more hands around the Mystery Shack."

Naruto playfully rolled his eyes as he saw that it was Stan's way of saying he was really looking forward for the visit. The man hasn't seen his relatives in years, and this was the first time in ages he'd get to reconnect with them. Still, something was bothering the blonde that he couldn't help but mention out loud, "I wonder if those two will be okay with all the strange things around here?"

It hadn't taken long for Naruto to notice that Gravity Falls wasn't a normal town even by Elemental Nations' standards. A lot of spooky and unnatural stuff happened in the area almost daily, and Naruto was still getting used to it all.

"They'll be fine, from what I've heard they're tough kids. Though remember, I want you keeping an eye on them this summer to make sure they don't get in over their heads but don't get _too_ involved. I'd rather they be safe for as long as they can before they go running off looking for trouble," Stan ordered as the bus finally pulled up.

"Don't worry boss man, Naruto Uzumaki is on the job!" Naruto declared while giving the man a thumbs up.

They then saw two kids get off the bus and realized that it could only be Dipper and Mable Pines. The siblings were twins, a boy and a girl, and were almost identical to each other. They both had bushy brown hair (though Mabel's was longer) and matching facial features, but other than that the two looked as different as night and day. Dipper Pines seemed fairly reserved and he wore a faded brown baseball cap, a navy blue vest, orange T-shirt, gray shorts, black sneakers, and a wristwatch. Mabel on the other hand was all smiles, showing off her braces, and she wore both a sweater and skirt that had so much color they made Naruto's old jumpsuit seem dull.

" **Those poor brats have no idea what they're getting into, do they?"** Kurama chuckled from his place in the seal.

'I guess we'll just have to wait and see,' Naruto thought as he and Stan got out of the cart to greet the twins. Little did any of them know on what all was to happen that summer in the small town of Gravity Falls.

1\. I did the math, and even though the show says he's pushing 70, Grunkle Stan should actually be between his late 50s or early 60s when the show starts. He was around 17-18 when he left the Pines family, then 10 years later he met with Ford and opened the Mystery Shack so he'd be around 27-28 when that happens, finally skip 30 years to the main story and he'd be 57-58 give or take a couple years. This also means that Dipper and Mabel's grandfather, who was a baby when Stan left, is only in his forties.


End file.
